In the initial phase of this project it is planned to compete a study upon phosphorylase B induced by the binding of substrate or modifier. The approach will be to monitor the interactive binding of a ligand and the allosteric activator AMP or the substrates glucose-1-phosphate or inorganic phosphate. The properties of the glucose effector site will also be examined, with particular attention to the thermodynamic parameters characterizing the binding of glucose, the interactive bindind of glucose and glucose-1-phosphate, and any conformational changes accompanying the binding of glucose. The subsequent phases of the research will be concerned with the activation and catalytic activity of phosphorylase kinase, the enzyme involved in the covalent activation of phosphorylase B. The points of interest will include the role of the alpha, beta, and gamma subunits in activity and regulation, the relationship of the different modes of activation, the origins of the Ca2 ion requirement for phosphorylase kinase activity, and the mechanism of phasphorylation of phosphorylase B. The final phase of the project will be concerned with the spatial relationship and organization of the protein components of the glycogen particules occurring in skeletal muscle and the bearing which this organization has upon the regulation of glycogenolysis.